The code linked below shows how to write a GUI in python using the Wx Python module. This particular script was written to analyze shell slices from a 3D Magneto Hydrodynamic code.
The key bit seems to be how to reference various "parent" classes to set status bars and menus of the main/original window. If you are familiar with Object-Oriented Programming, this is probably nothing new. I learned this on the fly so the code is most likely not well commented and may have a few bugs.
This tarball has all of the python dependency code as well as a sample data file so you can play around with the GUI.
When you initially start the program:
When you load a data file: